Oblique panoramic maps are panoramic maps that depict geographic areas in an oblique angle other than ninety degrees to depict map features, such as buildings or other landmarks, in relation to one another. At ninety degrees, the viewpoint of a map is from directly above the map features. Conversely, an oblique angle employs an angular viewpoint that is between zero degrees and ninety degrees to illustrate map features in a more representative depiction.
Cartographers in the 16th to early 19th centuries commonly employed oblique panoramic urban maps to illustrate urban areas. These maps made it easy for viewers to recognize landmark objects. However, the use of such maps disappeared with time as creating these types of maps involved extensive manual effort by skilled cartographers. Moreover, modern urban areas make such maps difficult to produce and use because of the large number of objects (e.g., buildings) that need to be included to make a representative map.
With the advent of modern technology, detailed modeling information is now available for many urban areas. Modeling information includes measurements and relative positions of objects in an area. Advances in computer graphics and visualization techniques have made it easier to render (e.g., draw or display) panoramic maps using this modeling information without the expense of sophisticated manual labor of cartographers. As an example, satellite imagery can be employed to render buildings on maps. This satellite imagery can be employed to render each building's façade. A façade of a building is a face of a building that generally includes windows and walls. For example, a skyscraper may have a different façade than a townhouse in terms of windows of different sizes and shapes. Users can distinguish one building from another based on the buildings' façades.
However, satellite imagery is unavailable from several positions and is often captured by satellites at different times of the day, and so shadows of objects can be in inconsistent places. Thus, when a viewer changes the viewpoint or zooms a map in or out, the buildings may not be illustratable in a visually pleasing form because of these inconsistencies. Moreover, collecting and storing satellite imagery from multiple viewpoints and times of day can be costly in terms of time and storage. However, not storing this information makes it difficult to reproduce façades of buildings.